All ECU and Start circuits are dead in my 2009 Santa Fe. Started when my climate controls and power windows stopped working while driving. Checked all fused circuits with test light and found that all ECU and Start circuits are dead. Found blown ignition fuse, replaced and as soon as i turned on ignition, it blew again. Replaced ignition switch, stopped blowing the fuse but now i have a no crank and my climate controls and power windows still are not working. Help!!

 

Not saying it is impossible, but it is rare for an ign sw to cause fuses to blow EXCEPT if what the switch feeds could have a short to ground.

There is a possibility that in the process of replacing the sw,you unknowingly made a temporary repair. This will require someone to have a wiring diagram to see exactly what the switch supplies power to.
If a wire that had a momentary connection was moved during the repair, it might have finished the job and opened the circuit completely. Because at this time it could be anything, all we can offer is speculation.